Well yeah, but if a book can never get published because of obscenity laws, it will never be discussed in a classroom. The law doesn't even need to be actually

Well yeah, but if a book can never get published because of obscenity laws, it will never be discussed in a classroom. The law doesn't even need to be actually enforced very often to have an effect. The fact that authors know that their books might be labeled as obscene will make them censor themselves.